Growth characteristics of D. alaskensis G20 grown in coculture with either M. maripaludis (A) or M. hungatei (B) in chemostats at a dilution rate of 0.027 h−1. The optical density (dashed line, ×), D. alaskensis G20 (♢), methanogen (□), and total cell number (△) are shown for a single coculture replicate. The continuous coculture was started at 65 or 110 h, respectively (indicated by arrow).